Arrangement for the forced air circulation in refrigerators and freezers

ABSTRACT

An arrangement for the forced air circulation in refrigerators and freezers, whose cabinet ( 10 ) defines at least one compartment ( 20, 30 ), a respective door ( 21, 31 ), and an air-cooling chamber ( 11 ) lodging an evaporator ( 12 ) and from which the compartment is supplied with a forced cooling air-flow. The arrangement comprises: at least one suction duct ( 40 ), incorporated to the door ( 21, 31 ) and which is provided with air inlets ( 41 ), opened to the interior of the respective compartment ( 20, 30 ), and with at least one air outlet ( 42 ) turned to the interior of the cabinet ( 10 ). A return fan ( 50 ) is mounted so as to draw the air from different levels of the front part of the compartment, and to form inside the suction duct ( 40 ) a return airflow that is directed to the air outlet ( 42 ) of the suction duct ( 40 ).

FIELD OF THE INVENTION

The present invention refers to a constructive arrangement to provide anadditional forced air circulation in the interior of the cabinet ofrefrigerators and freezers, particularly to increase air circulation inthe internal regions of the cabinet that are located close to the frontdoor of each compartment of said cabinet. The invention is intended tobe applied to refrigerators and freezers with a simple cabinet,presenting a single compartment with a respective front door, or twosuperposed compartments, each being frontally closed by a door.

PRIOR ART

It is known from the state of art that, in the cabinets of refrigeratorsand freezers, the highest temperatures are found in the regions close tothe door, which in the refrigerators usually incorporates differentshelves on which the products to be refrigerated are subject to saidtemperatures that are higher than those in the remaining parts of therefrigeration compartment of the cabinet.

The refrigeration deficiency mentioned above results from severalfactors, such as: gain of additional heat in the front regions of thecabinet through the door sealing gaskets; difficulty in supplying coolair to the front part of the cabinet or directly to the internal panelof the door; poor distribution of the forced airflow; low speed of theforced airflow when reaching the regions close to the door. Theexistence of this front region with a higher temperature has beenevidenced by thermodynamic tests.

The increase of the refrigerated airflow in the interior of the cabinet,particularly the increase of the refrigerated airflow directed to thecabinet region located adjacent to the front door, allows cooling morerapidly and intensively the load stored in the front region of thecabinet and thus reducing the temperature inside the cabinet, with noadditional energetic consumption being required from the refrigerationsystem, which thus becomes more efficient.

There are known different constructive solutions aiming at providing amore efficient cooling of the front region of the cabinets ofrefrigerators and freezers with forced air circulation.

In some of these solutions, such as those described in patent documentsU.S. Pat. No. 5,946,934; U.S. Pat. No. 5,979,174; U.S. Pat. No.5,584,191: U.S. Pat. No. 6,041,606 and U.S. Pat. No. 6,073,458, thesupply of cool air to the front region of the refrigeration compartmentor freezer compartment of a cabinet is achieved by conducting part ofthe forced airflow, coming from the air-cooling chamber within which islodged the evaporator, to the door region, through ducts incorporated tothe cabinet structure and which communicate with at least one ductformed in the door structure and which is provided with a plurality ofair outlets turned to the interior of the compartment. In these priorart solutions, the cool airflow to be directed to a compartment,generally the refrigeration compartment, is derived to the front regionof the cabinet through ducts provided in the structure of the latter,being then transferred to one or more ducts provided on the door of theappliance.

Although in the constructive arrangements mentioned above the coolairflow is supplied to the compartment region adjacent to the door, andalso to the region that is internal to the door shelves, it is stilldifficult to reach an efficient, intense and uniform cooling in saidcompartment region close to the door by means of a simple, durable andeconomically viable construction. Furthermore, these prior solutions donot promote a complete homogenization of the temperature in thecompartment when it is loaded with food, since the central region doesnot receive the same cool airflow that reaches the marginal regions andthose regions confronting the air outlets of the ducts. In some of thesesolutions, there is further provided a flexible connecting duct thatcouples the door duct with the cabinet duct, which connecting ductremains exposed to the movement of the door and thus susceptible toruptures with time.

With the purpose of eliminating the disadvantages mentioned above, thesolution object of U.S. Pat. No. 5,826,437 has been proposed, accordingto which the refrigeration compartment door is provided with a duct,having a median air inlet opened to the refrigeration compartment, andtwo or more air outlets, provided in the upper and lower regions of thedoor duct and which are also opened to the interior of the respectivecompartment. A fan is mounted to the air inlet to draw the air from theinside of the central front region of the compartment and to return itto the latter, through the air outlets and at a more intense ratedetermined by the fan, whose operation depends on the closing of thedoor and on the temperature conditions inside the compartment that aredetected by adequate sensors.

While eliminating the deficiencies of the solutions that use only coolairflow directional ducts, this solution of providing a fan in the doorduct is somewhat limited in terms of refrigeration efficiency. In thisprior solution, the fan draws the air from the median region of therespective compartment, returning it in the form of a circulatingairflow directed to different regions of the same compartment.

In this prior solution disclosed in U.S. Pat. No. 5,826,437, theadditional forced air circulation is effected by the air being drawnonly from the central front region of the compartment and discharged intwo opposite end regions of the same compartment. This suction from thecentral front region is insufficient to provide the displacement of thecooler air along the entire height of the compartment toward the frontdoor. Only the cool air mass located in the central region of thecompartment is forced to flow toward the front door. The lower and upperregions of the compartment close to the front door are not equallybenefited with the forced cool airflow coming from the rear region ofthe compartment, said lower and upper regions frontally receiving,directly, only the airflow drawn from the central front region. In thisprior solution, there is no displacement of cool air from the rearregion to the front region of the compartment along practically thewhole height thereof.

OBJECTS OF THE INVENTION

As a function of the above, it is an object of the present invention toprovide an arrangement for the forced air circulation in refrigeratorsand freezers, which overcomes the known constructive solutions,promoting an efficient homogenous refrigeration of the interior of thecompartment close to the front door thereof.

It is a further object of the present invention to provide anarrangement as mentioned above, which promotes an adequate refrigerationof the compartment region close to the respective front door, producinga reduction in the average temperature of said compartment.

It is another object of the present invention to provide an arrangementas mentioned above, which promotes an adequate refrigeration of theinternal front region of the compartment at a relatively shorter timethan that of the prior art solutions.

It is still a further object of the invention to provide an arrangementas mentioned above, which presents a simple construction, requiring nostructural alterations in the cabinet design.

SUMMARY OF THE INVENTION

Aiming at attaining the above-mentioned objects, the present inventionis directed to refrigerators and freezers of the type comprising acabinet, defining at least one compartment frontally closed by a door,and an air-cooling chamber lodging an evaporator, said compartment beingsupplied with a forced cooling airflow, coming from the air-coolingchamber, and provided with at least one air return duct directed to theair-cooling chamber.

According to the invention, the arrangement comprises at least onesuction duct incorporated to the door, extending along at least part ofthe height of the latter and which is provided along the extensionthereof with a plurality of air inlets opened to the interior of therespective compartment, and with at least one air outlet. A return fanis mounted to the suction duct, in order to draw the air from differentlevels of the front part of the compartment, in a closed door condition,through the air inlets of the suction duct, and to form inside thelatter a return airflow directed to the air outlet turned to theinterior of the cabinet.

In a preferred form of carrying out the invention, the air outlet of thesuction duct is arranged so that, upon the closing of the door, at leastpart of the return airflow is directed to the inside of the air returnduct, to be conducted to the air-cooling chamber.

The arrangement proposed herein can be further provided with adirectional duct, mounted to at least one of the parts defined by thedoor and the cabinet and which is provided with an inlet nozzle toreceive the return airflow from the suction duct, and an outlet nozzlewhich directs at least part of the return air to the inside of the airreturn duct of the compartment.

The present arrangement operates jointly with a means for sensing theoperational condition of the door and which allows the fan mounted tothe latter to be automatically driven by a control module of therefrigeration appliance only when the door is closed, as it usuallyoccurs with the fan operatively associated with the air-cooling chamberand which is responsible for the forced cooling airflow which is causedto pass through the compartment to be refrigerated.

BRIEF DESCRIPTION OF THE DRAWINGS

The present invention will be described below, with reference to theenclosed drawings given by way of example of possible embodiments forthe present arrangement, and in which:

FIG. 1 is a schematic longitudinal vertical sectional view of a combinedrefrigerator, whose cabinet defines an upper freezer compartment and alower refrigeration compartment, which compartments are frontally closedby respective doors and with the refrigeration compartment beingprovided with the arrangement for the forced air circulation of thepresent invention;

FIG. 2 is a front elevational view of the internal face of therefrigeration compartment door of the cabinet illustrated in FIG. 1;

FIG. 3 is an exploded perspective view of part of the arrangement forthe forced air circulation illustrated in FIGS. 1 and 2;

FIG. 4 is a view similar to that of FIG. 1, but illustrating the freezercompartment door also provided with the arrangement for the forced aircirculation of the present invention;

FIG. 5 is a front elevational view of the internal face of the freezercompartment door of the cabinet illustrated in FIG. 4; and

FIG. 6 is an enlarged vertical sectional view of the fan used in thesuction duct provided in the freezer compartment door, according to thearrangement for the forced air circulation illustrated in FIG. 4.

DETAILED DESCRIPTION OF THE INVENTION

As illustrated in FIGS. 1 and 4, the arrangement for the forced aircirculation of the present invention is directed to refrigerationappliances in the form of combined or not combined refrigerators andfreezers, whose cabinet 10 forms at least one refrigeration compartment20 or one freezer compartment 30, each being frontally closed by arespective door 21, 31.

The cabinet 10 further defines an air-cooling chamber 11 lodging anevaporator 12 of a refrigeration system, whose compressor is mounted inthe lower rear part of the cabinet 10. A refrigeration fan 14 is mountedinside the cabinet 10, in order to draw the refrigerated air from theair-cooling chamber 11 and to form a forced cooling airflow, which issupplied to the refrigeration compartment 20, to the freezer compartment30, or optionally to both the refrigeration compartment 20 and thefreezer compartment 30 in the case of the combined cabinets, asillustrated in FIGS. 1 and 4. The forced cooling airflow coming from theair-cooling chamber 11 and produced by the refrigeration fan 14 isconducted to the single compartment or to both the refrigeration andfreezer compartments 20, 30 of a combined cabinet 10, by means of supplyducts 22, 32, which can take different constructions such as thatexemplarily illustrated.

Each refrigeration compartment 20 and freezer compartment 30 is furtherprovided with at least one air return duct 23, 33 which is directed tothe air-cooling chamber 11, so as to obtain a forced circulation ofrefrigerated air in a closed circuit when the door or doors 21, 31is/are closed, between the air-cooling chamber 11 and the compartmentsdefined by the cabinet 10.

Considering the construction illustrated in FIGS. 1, 2 and 3, thearrangement for the forced air circulation according to the presentinvention comprises only one suction duct 40, which is incorporated tothe door 21 of the refrigeration compartment 20 longitudinally inrelation to said door 21 and extending along at least part of the heightof the latter. In case of being provided only one suction duct 40, it ispreferably located in the median region of the door 21, in order to betotally or partially embedded or not embedded at all in the thickness ofthe latter. In the example of the illustrated construction, the suctionduct 40 is partially embedded in the door 21, so as to have a front faceprojecting outwardly from the internal face 21 a of the door 21, asillustrated in FIGS. 1 and 2.

In the illustrated construction, in which only one suction duct 40 isprovided projecting outwardly from the median region of the door 21 ofthe refrigeration compartment 20, the shelves 25 of the door 21 are alsomedianly interrupted or at least narrowed in the region that issuperposed to the width of the suction duct 40. Depending on theconstruction of the suction duct 40, the shelves 25 of the door 21 canbe medianly interrupted.

The suction duct 40 is provided with a plurality of air inlets 41 whichare opened to the inside of the refrigeration compartment 29 when therespective door 21 is in a closed condition, said air inlets 41 beingprovided along the width and the length of the suction duct 40, in orderto maintain the interior of the latter in communication with theadjacent confronting front portion of the refrigeration compartment 20.

Still according to the illustrated construction, in which therefrigeration compartment 20 is the lower compartment of the cabinet 10,as shown in FIG. 1, the suction duct 40 presents an air outlet 42positioned as a single air outlet at the upper end of the suction duct40.

Since the door 21 of the refrigeration compartment 20 is provided withshelves 25, the air outlet 42 is defined at an end portion 43 with awidened depth of the suction duct 40 projecting outwardly from the frontface of the latter, ending at a level that is above or below the levelof the upper shelf 25 of the door 21.

Another component of the present arrangement is defined by a return fan50, which is mounted to the suction duct 40 so as to draw the air fromdifferent levels of the front portion of the refrigeration compartment20 in a closed condition of the door 21, through the air inlets 42 ofthe suction duct 40, and to form inside the latter a return airflowwhich is directed to the air outlet 42 of the suction duct 40.

The air outlet 42 of the suction duct 40 is preferably dimensioned andpositioned in such a way as to conduct the return airflow to an internalregion of the respective compartment 20, 30 located close to an inletwindow 23 a, 33 a of the air return duct 23, 33 of the refrigerationcompartment 20 or freezer compartment 30.

The constructive arrangement mentioned above allows the air drawn by thesuction duct 40 to be at least partially returned to the air-coolingchamber 11 through the air return duct 23, 33 and not entirely returnedto the respective compartment.

Regarding the refrigeration compartment 20, there can be furtherprovided a directional duct 60, affixed to at least one of the partsdefined by the door 21 and the cabinet 10 and which presents an inletnozzle 61, which is arranged to receive the return airflow from thesuction duct 40, and an outlet nozzle 62, which is turned to the insideof the refrigeration compartment 20.

In the construction illustrated in FIGS. 1, 2 and 3, the return fan 50comprises a rotor 51 mounted inside a tubular shell 55, which iscoaxially coupled, by an open end, to the air outlet 42 of the suctionduct 40 and with its also open opposite end being coupled to the inletnozzle 61 of the directional duct 60. In this exemplificativeconstruction, the directional duct 60 comprises an inlet portion 60 a,coaxial to the air outlet 42 of the suction duct 40 and which carriesthe inlet nozzle 61, and an outlet portion 60 b, constructed so as todefine an outlet nozzle 62 in the form of a window with small height andhaving a width which can be quite larger than that of the suction duct40. In this arrangement, the return fan 50 and the air outlet 42 havethe same axis which is parallel to the longitudinal axis of the suctionduct, and the inlet nozzle 61 and the outlet nozzle 62 of the suctionduct have their axes lying in distinct directions, with the axis of theinlet nozzle 61 coinciding with the axis of the return fan 50 and of theair outlet 42 of the suction duct 40.

In order to allow the air drawn from the front portion of therefrigeration compartment 20 to be at least in great part returned tothe air-cooling chamber 11, the directional duct 60 is shaped so thatits outlet nozzle 62 directs the return airflow to the inside of therespective inlet window 23 a of the air return duct 23 of therefrigeration compartment 20, as better illustrated in FIG. 1.

With this constructive arrangement, the air which is drawn from thefront portion of the refrigeration compartment 20 close to the door 21,is returned at least in great part to the air return duct 23 and to theair-cooling chamber 11, in order to have its temperature lowered by theevaporator 12, before being returned to the interior of therefrigeration compartment 20 through the supply duct 22.

It should be understood herein that in the combined appliances in whichthe refrigeration compartment 20 is provided over the freezercompartment 30, the air outlet 42 of the suction duct 40 is preferablypositioned at the lower end of the latter, adjacent to the dividing wall16 of the cabinet 10 that separates the compartments from each other.This arrangement allows the air outlet 42 of the suction duct 40 to bepositioned closer to the air return duct 23 directed to the air-coolingchamber 11.

As illustrated in FIGS. 4, 5 and 6, the present arrangement for theforced air circulation can be also applied to the freezer compartment30. In this case, the door 31 of this compartment is provided with aninternal face 31 a from which projects a suction duct 40, similar tothat of the door 21 of the refrigeration compartment 20 and which isprovided with air inlets 41 that are turned to the inside of the freezercompartment 30, and with an air outlet 42 which is generally positioned,at the lower end of the suction duct 40, adjacent to the dividing wall16 of the cabinet 10 in the refrigeration appliances of the combinedtype in which the freezer compartment 30 is provided over therefrigeration compartment 20.

The suction duct 40 provided in the door 31 of the freezer compartment30 can have its air outlet 42 presenting an axis orthogonal to the planeof the door 31 and configured so as to receive and secure a tubularshell 55 of a return fan 50.

In this case, the return fan 50 can discharge the return airflowdirectly inside the freezer compartment 30 and preferably close to theinlet window 33 a of the air return duct 33, with no need of providing adirectional duct 60 similar to that provided in the refrigerationcompartment 20. However, it should be understood that the freezercompartment 30 could be also provided with a directional duct 60, incase its existence is required as a function of the compartment design.

In this arrangement, the return fan 50 and the air outlet 42 have thesame axis, which is orthogonal to the longitudinal axis of the suctionduct 40.

As it can be noted, the arrangement of the present invention allows theair contained in the front region of any of the compartments 20, 30 ofthe cabinet 10 to be drawn by the return fan 50 mounted in the door 21,31, and to be returned, at least in great part, to the air-coolingchamber 11. In order to facilitate the conduction of the return airflowto the air-cooling chamber 11, it is preferred that the outlet 42 of thesuction duct 40, provided or not with the directional duct 60, bepositioned close to the air return duct 23, 33 already designed for therespective compartment 20, 30 and which in the case of the combinedcabinets, is generally provided in the region of the dividing wall 16.

While only one embodiment of the invention has been illustrated, itshould be understood that changes in the form and arrangements could bemade without departing from the inventive concept defined in theappended claims.

1. An arrangement for the forced air circulation in refrigerators andfreezers of the type comprising a cabinet (10) defining at least onecompartment (20, 30) frontally closed by a respective door (21, 31), andan air-cooling chamber (11) lodging an evaporator (12), said compartmentbeing supplied with a forced cooling airflow coming from the air-coolingchamber (11) and provided with an air return duct (22, 33) directed tothe air-cooling chamber, characterized in that it comprises: at leastone suction duct (40) incorporated to the door (21, 31), extending alongat least part of the height of the latter and being provided, along theextension thereof, with a plurality of air inlets (41) opened to theinterior of the respective compartment (20, 30), and with at least oneair outlet (42) turned to the interior of the cabinet (10); and a returnfan (50) mounted to the suction duct (40), in order to draw the air fromdifferent levels of the front part of the compartment (20, 30) in aclosed door condition, through the air inlets (41) of the suction duct(40), and to form inside the latter a return airflow directed to the airoutlet (42) of the suction duct (40).
 2. The arrangement as set forth inclaim 1, characterized in that the air outlet (42) of the suction duct(40) is arranged so that, with the closing of the door (21, 31), atleast part of the return airflow is directed to the inside of the airreturn duct (23, 33) of the compartment (20,30).
 3. The arrangement asset forth in claim 1, characterized in that the return fan (50) ismounted close to the air outlet (42) of the suction duct (40).
 4. Thearrangement as set forth in claim 3, characterized in that the returnfan (50) presents a shell (55) having an end coupled to the air outlet(42) of the suction duct (40) and an opposite end opened to the insideof the respective compartment (20, 30).
 5. The arrangement as set forthin claim 4, characterized in that the return fan (50) and the air outlet(42) of the suction duct (40) have the same axis, which is parallel tothe longitudinal axis of the suction duct (40).
 6. The arrangement asset forth in claim 3, characterized in that the return fan (50) and theair outlet (42) have the same axis, which is orthogonal to thelongitudinal axis of the suction duct (40).
 7. The arrangement as setforth in claim 1, characterized in that it further comprises adirectional duct (60), mounted to at least one of the parts defined bythe door (21, 31) and the cabinet (10) and which presents an inletnozzle (61) receiving the return airflow from the suction duct (40) andan outlet nozzle (62), which upon the closing of the door (21, 31)directs at least part of the return airflow to the inside of the airreturn duct (23, 33) of the respective compartment (20, 30).
 8. Thearrangement as set forth in claim 7, characterized in that the inletnozzle (61) and the outlet nozzle (62) of the directional duct (60) havetheir axes lying in distinct directions, the inlet nozzle (61) havingthe axis coinciding with that of the return fan (50) and of the airoutlet (42) of the suction duct (40).
 9. The arrangement as set forth inclaim 1, characterized in that the suction duct (40) is located in themedian region of the door (21, 31) and provided with air inlets (41)along the width and length thereof.
 10. The arrangement as set forth inclaim 1, characterized in that the suction duct (40) has its depthpartially embedded in the thickness of the door (21, 31), in order tohave a front face projecting outwardly from the internal face (21 a, 31a) of the door (21, 31).
 11. The arrangement as set forth in claim 1 andwhich is applied to a combined refrigerator provided with arefrigeration compartment (20) and a freezer compartment (30) which aresuperposed and separated from each other by a dividing wall (16),characterized in that the suction duct (40), which is provided in any ofthe doors (21, 31) of the two compartments, has the air outlet (41)positioned at an end portion (43) turned to said dividing wall (16). 12.The arrangement as set forth in claim 1, characterized in that the airoutlet (42) of the suction duct (40) is defined at an end portion (43)of the latter, presenting a widened depth.